Medical Expulsive Therapy in Urolithiasis: A Review of the Quality of the Current Evidence

Ureteral wall thickness as a predictor for non-invasive treatment success for steinstrasse. Can we save time?

PURPOSE

We aimed to define factors affecting the non-invasive overall treatment success (medical expulsive therapy (MET) ± shock wave lithotripsy (SWL)) for uncomplicated ureteral steinstrasse (SS) clearance.

METHODS

We retrospectively evaluated consecutive patients who underwent SWL for renal stones between 2017 and 2021. Patients with uncomplicated SS were included. All patient's demographic and radiological data, e.g., age, gender, pre-SWL stenting, SS site, type, leading stone size in widest diameter (< 10 mm and ≥ 10 mm), ureteral wall thickness (UWT) in mm against the leading stone were collected. If SS was diagnosed, medical treatment was given for 4 weeks. In case of MET failure, either SWL for the leading stones + MET or direct URS was done. Non-invasive treatment success (SFR) was considered if complete clearance of SS occurred with no complications or the need for invasive intervention.

RESULTS

A total of 145 patients were included with mean age of 45.9 ± 12.4 years. SFR in case of MET only occurred in 27.9%. Complications happened in 26 patients (17.9%). Non-invasive treatment SFR was achieved in 78 patients (53.8%) totally where SS type I, leading stone size ≤ 10 mm type and decreased UWT around the leading stone increased treatment success.

CONCLUSION

Ureteral wall thickness is an important factor predicting SS management success. Besides the decreased UWT, non-invasive management should be offered for type I SS with leading stone ≤ 10 mm.

Effect of α1D-adrenoceptor blocker for the reduction of ureteral contractions

PURPOSE

Urolithiasis is a common urinary tract disease with growing prevalence. Alpha1-adrenoceptors (α1-ARs) are abundant in ureteral smooth muscle, distributed with different α1-AR subtypes. α1D-AR is the most widely distributed in the ureter. However, the effect of α1D-AR blockade on ureteric contraction remains unknown.

MATERIALS AND METHODS

We dissected smooth muscle tissues (3 mm×3 mm) from the rat bladder and human ureter, tied silk strips on both tissue ends, and measured contraction in an organ bath chamber. Contraction activity in ureteral smooth muscle cells (USMCs) was immunocytochemically examined using primary rat and human USMC cultures.

RESULTS

Using the organ bath system, we determined the inhibitory effects of silodosin, tamsulosin, and naftopidil. Naftopidil significantly decreased contractility of rat bladder tissue; similar results were observed in human ureteral tissue. To confirm ex vivo experimental results in vitro , we examined the phosphorylation of myosin light chain (MLC), a marker of contractility, in a primary human USMC culture. The examined drugs decreased phospho-MLC levels in human USMCs; however, naftopidil profoundly increased MLC dephosphorylation.

CONCLUSIONS

We studied the effects of naftopidil, an α1D-AR inhibitor, on the ureter. Compared with alpha-blockers, naftopidil significantly relaxed ureteral smooth muscle. Therefore, naftopidil could be an effective therapy for patients with ureteral stones.

Endoscopic Combined Intrarenal Surgery vs Percutaneous Nephrolithotomy for Large and Complex Renal Stone: A Systematic Review and Meta-Analysis

Background: Managing complex and large renal stones with percutaneous nephrolithotomy (PCNL) is difficult because of the likelihood of residual stones and multiple access. Endoscopic combined intrarenal surgery (ECIRS) is introduced as an improvement to the procedure to manage stones in one session. The objective of this systematic review and meta-analysis is to compare the efficacy and safety between ECIRS and PCNL for treating large and complex renal stones. Materials and Methods: We conducted a systematic review in the Embase, Scopus, and MEDLINE databases based on the 2020 Preferred Reporting Items for Systematic Review and Meta-Analyses guideline. Eligible studies comprised both randomized and nonrandomized studies comparing ECIRS and PCNL. Results: A total of five nonrandomized studies and one randomized controlled trial were included. The analysis was divided into two subgroups based on the PCNL type, a conventional PCNL (cPCNL) and a mini-PCNL (mPCNL). The one-step stone-free rate (SFR) of ECIRS were significantly higher compared with both the cPCNL (odds ratio [OR] 5.14, 95% confidence interval [CI] 2.54 to 10.4, p < 0.001) and mPCNL (OR 4.27, 95% CI 2.57-7.1, p < 0.001). There were no significant differences in mean operative time and hemoglobin drop between both groups (p > 0.05). The use of auxiliary procedures was significantly higher in both PCNL groups compared with the ECIRS group (OR 0.19, 95% CI 0.13-0.30, p < 0.001). The overall complication rate of ECIRS was lower compared with PCNL (OR 0.43, 95% CI 0.21-0.85, p = 0.02), especially urosepsis, in which the incidence was lower compared with cPCNL (OR 0.14, 95% CI 0.02-0.78, p = 0.02), but not mPCNL (p > 0.05). Conclusion: ECIRS is an effective and safe treatment particularly for large and complex nephrolithiasis, with significantly higher one-step SFR, a lower necessity for auxiliary procedures, and a lower complication rate compared with PCNL.

Fragility index of urological literature regarding medical expulsive treatment

INTRODUCTION

The role of medical expulsive treatment (MET) is controversial. Fragility index is an additional metric to assess randomized controlled trials (RCTs) outcome validity and indicates how many patients would be required to convert a trial from being statistically significant, to not significant. The larger is the FI, the better the trial's data. The aim of this study is to assess FI of RCTs regarding MET for ureteral stones.

MATERIALS AND METHODS

A systematic literature search was performed. RCTs, reporting stone expulsion as a dichotomous outcome, showing statistical significance were eligible. FI (the number of patients needed to change from a non-event to event group, to lose statistical significance) and Fragility quotient (FI divided by total sample size), were calculated while Pearson's correlation and Mann-Whitney U test were used as appropriate.

RESULTS

Thirty-six RCTs were eligible, with median FI = 3.5 and fragility quotient = 0.042, median sample size = 81, median journal impact factor = 1.73 and median reported p value = 0.008. In 33.3% of the studies, number of patients lost during follow-up was larger than FI, while in 13.89% of the studies, FI was 0, indicating use of inappropriate statistical method. Pearson's correlation showed significant positive association between FI and sample size (r = 0.981), number of events (r = 0.982) and impact factor (r = 0.731), while no association was found with p value or publication year.

CONCLUSIONS

In this analysis, a calculated FI of 3.5 indicates that findings from RCTs on MET for ureteral stones are fragile and should be interpreted in combination with clinical thinking and expertise.

The safety and efficacy of doxazosin in medical expulsion therapy for distal ureteric calculi: A meta-analysis

Purpose

Alpha-adrenergic receptor blockers can be effectively used in the context of medical expulsion therapy (MET) to treat ureteric stones. This study was designed to evaluate the safety and efficacy of doxazosin in MET relative to placebo or tamsulosin.

Methods

We systematically searched the PubMed, the Cochrane Library, EMBASE, Chinese Academic Database, and Web of Science databases to select randomized controlled trials (RCT) that compared the use of doxazosin with placebo or tamsulosin to treat ureteric stones. All patients we included were limited to those diagnosed with visible stones in the distal ureter. The diameter of ureteric stones does not exceed 10 mm.

Results

Eight trials comparing doxazosin with placebo or tamsulosin containing 667 patients were assessed in the final analysis. The meta-analysis showed that doxazosin effectively treated ureteric stones and was better than placebo in terms of efficacy. Relative to the placebo group, the expulsion rate of stones from the distal ureter (OR = 3.00, 95% CI [2.15, 4.19], I2 = 0%, P < 0.00001) was significantly increased, and the expulsion time (days) was shortened (mean difference) (MD) = −4.03, 95% CI [−4.53, −3.53], P < 0.00001). The doxazosin group experienced fewer pain episodes (MD = −0.78, CI = [−0.94, −0.23], I2 = 0%, P < 0.00001) than the placebo group. A subgroup analysis showed that the doxazosin group had a higher expulsion rate (of 5–10 mm stones) compared with the placebo group. Although doxazosin resulted in significantly more adverse effects compared with the placebo, the patient’s symptoms were mild and no further medical interventions were required. Moreover, the expulsion time (days) was shorter for patients receiving doxazosin (MD = −0.61, 95% CI [−0.97, −0.24], I² = 39%, P = 0.001) than those receiving tamsulosin.

Conclusion

Compared with the placebo group, patients receiving doxazosin had a greater expulsion rate, a reduced expulsion time, and fewer pain episodes. The expulsion time of doxazosin was shorter than that of tamsulosin.

Medical treatment of urinary stones

PURPOSE OF REVIEW

To identify the latest progression on medical treatment of urinary stones.

RECENT FINDINGS

Nonsteroidal anti-inflammatory drugs should be the preferred analgesic option for patients presenting to the emergency department with renal colic. A-blockers could be of patient benefit when used for distal ureteral stones more than 5 mm in size. However, the quality of the randomized controlled studies on medical expulsive therapy (MET) is still low based on the Consolidated Standards for Reporting Trials (CONSORT) criteria. MET should be used with caution in children and pregnant women. In patients with renal stones, the evaluation of the comorbidities of developing chronic Kidney Disease (CKD) or End Stage Renal Disease (ESRD) is mandatory. It is highly recommended to follow the European Association of Urology Urolithiasis Guidelines Panel Diagnostic and Therapeutic algorithms to prevent stone recurrence.

SUMMARY

Medical treatment of urinary stone disease should be supported by well designed higher level of evidence clinical research.

Silodosin versus tamsulosin for medical expulsive treatment of ureteral stones: A systematic review and meta-analysis

Silodosin, a recently introduced selective α-blocker, has a much higher selectivity for the α-1A receptor. The efficacy and safety of silodosin compared to tamsulosin in medical expulsive therapy (MET) are controversial. The objective of this study was to assess the efficacy and safety of silodosin compared to tamsulosin for treating ureteral stones <10 mm in diameter. We systematically searched the PubMed, EMBASE, Cochrane library, and Scopus databases from their inception to May 2018. We included randomized controlled studies (RCTs) and observational studies, which investigated stone expulsion rates using silodosin compared to tamsulosin. Data were synthesized using a random-effects model. Sixteen studies with 1824 patients were eligible for inclusion. Silodosin achieved significantly higher expulsion rates than tamsulosin (pooled risk difference (RD): 0.13, 95% confidence interval (CI): 0.09 to 0.18, GRADE: high). A subgroup analyses showed that silodosin has a significantly higher expulsion rate on stone sizes of 5-10 mm than tamsulosin (pooled RD: 0.14, 95% CI: 0.06 to 0.22, I2 = 0%). The superior effect was not observed on stone sizes <5 mm. A multivariate regression showed that the RD was negatively associated with the control expulsion rate after adjusting for age and gender (coefficient -0.658, p = 0.01). A sensitivity analysis showed that our findings were robust. Patients receiving silodosin also probably had a significantly shorter expulsion time (pooled mean difference (MD): -2.55 days, 95% CI: -4.06 to -1.04, I2 = 85%, GRADE: moderate) and may have fewer pain episodes (pooled MD: -0.3, 95% CI: -0.51 to -0.09, GRADE: low) but a higher incidence of retrograde ejaculation by 5% compared to those receiving tamsulosin. In conclusion, compared to tamsulosin, silodosin provided significantly better stone passage for patients with ureteral stones (particularly for sizes of 5~10 mm), shorter expulsion times, and fewer pain episodes but caused a higher incidence of retrograde ejaculation.

Effect of Tamsulosin on Passage of Symptomatic Ureteral Stones: A Randomized Clinical Trial

IMPORTANCE

Urinary stone disease is a common presentation in the emergency department, and α-adrenergic receptor blockers, such as tamsulosin, are commonly used to facilitate stone passage.

OBJECTIVE

To determine if tamsulosin promotes the passage of urinary stones within 28 days among emergency department patients.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a double-blind, placebo-controlled clinical trial from 2008 to 2009 (first phase) and then from 2012 to 2016 (second phase). Participants were followed for 90 days. The first phase was conducted at a single US emergency department; the second phase was conducted at 6 US emergency departments. Adult patients were eligible to participate if they presented with a symptomatic urinary stone in the ureter less than 9 mm in diameter, as demonstrated on computed tomography.

INTERVENTIONS

Participants were randomized to treatment with either tamsulosin, 0.4 mg, or matching placebo daily for 28 days.

MAIN OUTCOMES AND MEASURES

The primary outcome was stone passage based on visualization or capture by the study participant by day 28. Secondary outcomes included crossover to open-label tamsulosin, time to stone passage, return to work, use of analgesic medication, hospitalization, surgical intervention, and repeated emergency department visit for urinary stones.

RESULTS

The mean age of 512 participants randomized to tamsulosin or placebo was 40.6 years (range, 18-74 years), 139 (27.1%) were female, and 110 (22.8%) were nonwhite. The mean (SD) diameter of the urinary stones was 3.8 (1.4) mm. Four hundred ninety-seven patients were evaluated for the primary outcome. Stone passage rates were 50% in the tamsulosin group and 47% in the placebo group (relative risk, 1.05; 95.8% CI, 0.87-1.27; P = .60), a nonsignificant difference. None of the secondary outcomes were significantly different. All analyses were performed according to the intention-to-treat principle, although patients lost to follow-up before stone passage were excluded from the analysis of final outcome.

CONCLUSIONS AND RELEVANCE

Tamsulosin did not significantly increase the stone passage rate compared with placebo. Our findings do not support the use of tamsulosin for symptomatic urinary stones smaller than 9 mm. Guidelines for medical expulsive therapy for urinary stones may need to be revised.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00382265.

[Extracorporeal shock wave lithotripsy]

Interventional treatment of stones essentially consists of three treatment modalities. Extracorporeal shockwave lithotripsy (ESWL), in addition to uterorenoscopy (URS) and percutaneous nephrolitholapaxy (PCNL) is an essential treatment pillar and is the only noninvasive therapy option for the treatment of urinary stones. After a long period of ESWL being the leading choice in stone treatment, the number of SWL interventions diminished in recent years in favor of the other two treatment modalities (URS and PCNL). This article describes the indications, surgical technique and management of complications of SWL.